Rectifier circuit



p 1939- E. o. ROGGENSTEIN 2,172,759

RECTIFIER C IRCUI'I' Original Filed Sept. 22, 1936 2 Sheets-Sheet 1INVENTOR E O. ROGGENSTEIN w BY $14M HI ATTORNFY Sept. 12, 1939. E. o.ROGGENSTEIN RECTIFIER CIRCUIT Original Filed Sept. 22, 1936 2Sheets-Sheet 2 llllllllllllllllll INVENTOR E .O. ROGGENSTEIN M155 zo9rax-Llqsz 137 LI -456 HIS ATTORNEY Patented Sept. 12, 1939 UNITED STATESRECTIFIER CIRCUIT Edwin 0. Roggenstein,

Ilion, N. Y., assignor to Remington Rand Inc., Buffalo, N. Y., acorporation of Delaware Original application September 22, 1936, SerialNo. 101,903. Divided and this application September 24', 1938, SerialNo. 231,524

4 Claims.

This invention relates to rectifiers and their associated circuits, andrelates particularly to matter divided from my copending application 5.N. 101,903 filed September 22, 1936, now Pat- .5 ent No. 2,151,232,issued March 21, 1939, for a Portable universal electric punch.

The invention herein described relates more particularly to dryrectifiers and their associated circuits which have improved regulationcharacteristics.

Many portable machines such as punches, electric typewriters, and otherelectrical devices, require a direct current power supply. When a sourceof direct current power is available the machine may be a small portabledevice. When direct current is not available, however, it is necessaryto provide some sort of rectifier. One manner in which this has beendone has been to use a motor generator from which a single ma chine or anumber of machines may be operated. Such a motor generator is. ofcourse, a large, heavy, and expensive piece of equipment, andsubstantially increases the cost of operation.

At the present time no dry rectifier has been 25 designed for use with apunch, which will supply a high enough voltage so that the current willbe low enough for efficient operation, and which is small and lightenough to be built into the device so that it may still be portable. Ithas so also been impossible to build a portable dry rectifier for thesame reason, that is, so many sections of rectifier are required inorder to have high enough voltage, and to provide an adequate margin ofsafety for satisfactory operation, that such 35 a rectifier would bevery large, heavy, and cumbersome and could not be included with aportable device.

The practice where the source of power is alternating has, therefore,heretofore always been to provide a separate rectifier whichnecessitated that the operated device be used within a limited distancefrom such rectifiers.

One of the objects of the invention is the provision of a dry discrectifier which is assembled in such a manner as to provide an adequatesource of direct current for the operation of a small machine fromeither an alternating or direct current power source.

Another object of the invention is the provision of an electricalcircuit in connection with such a dry rectifier which will permit theoperation of small devices from alternating or direct current.

Another object of the invention is the provision of an alternativecircuit which may be used for either A. C. or D. C. operation by themanipulation of a switch depending on which source of power is supplied,and which with D. C. supply will operate with either polarity of currentap plied to the terminals of the circuit.

Another object of the invention is the provision of the novel rectifierarrangements referred to above, as well as others to be described below,for whatever uses their operating characteristics are suitable.

Other objects and features of the invention will be apparent from thefollowing description of the drawings, in which Fig. 1 is a circuitdiagram showing one circuit which may be used in a portable punch orother magnet, operated machine and showing diagrammatically thepreferred rectifier assembly;

Fig. 2 is a schematic diagram of the circuit and apparatus shown in Fig.1;

Fig. 3 is a diagram of an alternative circuit and rectifier assembly tothat shown in Fig. 1;

Fig. 4 is a schematic diagram of the circuit and apparatus shown in Fig.3;

Fig. 5 is a graph illustrating the fluctuations in a source ofalternating current;

Fig. 6 is a graph showing the form of rectified current provided by thecircuit and apparatus shown in Figs. 1 and 3 when operating in each casefrom an alternating current power source;

Fig. 7 is a schematic diagram of an alternative half-wave rectifiercircuit for A. C. or D. C. operation, using only 20 rectifyingjunctions;

Fig. 8 is an enlarged exploded view of a portion of the rectifier ofFig. 1.

Similar parts have the same reference numerals throughout the drawings.

In describing the novel features of this machine, reference is made tothe circuit diagrams of Figs. 1 and 2. In Fig. 1, is indicateddiagrammatically the new rectifier assembly. This rectifier may be madeof dry contact rectifying discs of the copper oxide or magnesium coppersulphide type, such as are well known and are described, for example, inUnited States patents to Ruben No. 1,649,741, of November 15, 1927, No.1,751,361, of March 18, 1930, and No. 1,751,460, of March 18, 1930, andwill be referred to hereafter as simply a copper oxide rectifier.Rectifiers using such discs are manufactured and sold commercially asRectox rectifiers.

In Fig. l a number of these discs are shown in one arrangement in whichthe discs are held together by a central bolt H3 which is insulated fromthe assembly by an insulating cylinder H4 and which holds the assemblytogether under pressure by the nut H5 which bears against a heavy discH6 insulated from the assembly by an insulator H1. At the other end ofthe assembly there is a washer I 18, another heavy disc H9, and anotherinsulator I20, all of which cooperate to hold the rectifying discstogether un der pressure.

At the left of the assembly of the rectifier proper is a conducting discl2| which may be of brass. Pressed against this disc is a copper discI22 (see Fig. 8) having a surface coating of copper oxide or magnesiumcopper sulphide or any other material which will perform the samefunction. the jagged line. This surface is on the right hand side of thecopper discs between the discs of 112i and I24 of Fig. 1. Pressedagainst the copper oxide surface of the first disc I22 is a lead discI23. The assembly continues with successive copper oxide and lead discs,with the copper oxide coating facing in the same direction until asecond conducting disc I24, which may also be of brass, is reached.There is a lead washer next to the disc I26 on each side. From thispoint the assembly continues with successive lead and copper discs, butit will be noted that at this point the direction in which the copperoxide surfaces face is reversed from the direction in which thesesurfaces faced between the discs I2I and I2 1. They continue facing inthe new direction until another conducting disc which may also be ofbrass, is reached, and at this point the direction again reverses. Theassembly continues until a fourth conducting disc I25, which may againbe of brass, is reached, which is at the right hand edge of therectifier assembly proper as seen in Fig. 1. A lead disc is placed justnext to the disc I225. The direction in which current will flow througheach section of this assembly is indicated by the arrows below thesections. The rectifier of Fig. 1 comprises approximately 30 copperoxide discs, ten in each section.

In Fig. 8 is shown an enlargement of a portion of Fig. 1 so thestructure may be seen in more detail.

The terminals I2'I and I28 may be connected to any power line ofalternating current of 110 to 150 volts. A switch I29 and a fuse I38 areprovided in the power circuit. A pair of contacts ISI and I32 isconnected in this portion of the circuit and a condenser I33 isconnected across them to prevent sparking.

In describing these circuits, both in what has been said above and whatwill follow, that portion of the circuit between the input terminals INand I28 up to the rectifier, will be called the power circuit, and thatportion of the circuit beyond the rectifier", the load circuit.

Connected across the discs I24 and I25 is a resistance I34, Figs. 1 and2, which in a preferred embodiment of the invention is approximately 250ohms. From the disc I24 the load circuit goes by conductor I35, throughcontacts I36 and IB'I, to conductor I38, magnet 83, the windings ofwhich may be connected in parallel, conductor ISS, back to the disc I25on the other side of the resistance IS I. The condenser I09 is connectedacross the contacts I36 and I31 to prevent sparking The rectifierassembly of Fig. 1 is such that if a positive potential is applied tothe terminal I28 and of course if the switch I29 and contacts I3I andare closed, a current will pass from the right to the left in thesection of the rectifier from disc I2 3 to disc I25. At the disc I25 itwill be noted again that the direction in which the copper oxidesurfaces of the copper discs face between and I2 3 is different from thedirection in which they face between the discs I 26 and Between thediscs I25 and I24, therefore, no current will pass except leakagecurrent. At the disc I24 the direction of the copper oxide surface isagain reversed so that current would pass between the discs I24 and I2I. As the recti- The coated surface is indicated by fier thereforepermits current to flow from disc I26 to disc I25 and from disc I24 todisc I2I it will be seen that a circuit may be completed across thediscs I25 and I24 and therefore by this connection current will bepermitted to flow through the circuits of the load.

If a positive potential is applied to the terminal I 27 no current canflow between the discs I2I and I24 nor can current flow between thediscs I25 and I26 so that the machine will not operate from a directcurrent power source unless the connectionis made with the properpolarity.

If an alternating current power source is connected across the terminalsI21 and I28 the rectifier will operate to rectify the positive pulses ofpotential applied to the terminal I28 and pass current in this directionin the same manner as it passes direct current applied with the positivepotential to terminal I28. This is illustrated in Figs. 5 and 6.

In Fig. 5 the fluctuations of an alternating current source is shown andin Fig. 6, the rectified positive pulses are shown. It will thus be seenthat when operating from alternating current a pulse passes through therectifier for each positive half cycle on the terminal I28 and that thisrectified current is permitted to fiow through the load circuit acrossthe discs I25 and I2 4. The wave shape of the rectified pulses is notknown exactly, so Fig. 6 is simply illustrative of the operation as totime.

When it is desired to use this circuit for intermittent duty with loadssuch as punches, bells, and other signalling equipment, the actuatinglever of the device is arranged so as to make contacts I3I, I32, andI36, IS'I simultaneously at the start of the action and to break them atthe finish.

In Fig. 2 is shown a schematic diagram of the circuit in Fig. l andcorresponding parts are similarly numbered. Here is shown a rectangleI22 and a solid triangle I23 to indicate a section of the copper oxiderectifier. The current flow is in the direction of the point of thesolid triangle. It will be seen from Fig. 2 that when a positive sourceof current is applied to the terminal I28 it cannot pass through themiddle portion of the rectifier due to the direction of flow from I25 toI24 but it can pass through both end sections of the rectifier and thecircuit can be completed through the load circuit.

In Figs. 3 and 4 is shown an alternative circuit arrangement which mayalso be used for operating from alternating or direct current. In thiscircuit the polarity of the D. C. source does not matter as the circuitwill operate equally well whichever polarity is present on the terminalsIE? or I28. In this circuit the rectifier is assembled just as beforeexcept that an insulating disc MB and an extra conducting disc I4! areinserted at the positions shown. A double-pole, doublethrow switch M2 isprovided which for operation on direct current is thrown to its lowerposition (Fig. 3) to connect with the terminals I48 and I49. Inoperating on direct current, therefore, with the terminals I48 and M9connected to the terminals I and M6 through the switch I42, the circuitis as follows: From terminal I21, through switch I29, fuse ISE, terminalI48, switch I42, terminal I45, contacts I36 and I31, conductor I38,magnet 33, resistance I56, which simply reduces the amount of current sothat it will not exceed current drawn by the machine when operating fromalternating current disc I25, to terminal I46, switch I42, terminal I49,

contacts I3I and I32, back to terminal I28. It will thus be seen thatwhen operating on direct current with this circuit the rectifier iscompletely shunted out of the circuit and it is for this reason that thepolarity of the current supplied to the terminals I21 and I28 does notmatter. It will also be noted that the resistance I50 permits thecurrent drawn by the load to be reduced so that it does not exceed thecurrent drawn by the machine when operating on alternating current. Itis provided because the rectifier is shunted out of the circuit. It alsoavoids the use of a switch such as the switch I8I of Figs. 1 and 2.

When operating the circuits of Figs. 3 and 4 on alternating current, theswitch I42 is thrown to its upper position (Fig. 3) so that it makescontact with terminals I43 and I44. The circuit is then from terminalI28, through contacts I3I, I32, disc I26 through the section of therectifier from disc I26 to disc I25, through terminal I46, switch I42,terminal I44, magnet 83, conductor I38, contacts I36 and I31, disc I24,through the section of the rectifier from disc I24 to disc I2I, throughfuse I30 and switch I29, back to terminal I21. It will be noted that theinsulating disc I is short-circuited by the connection from disc I24,terminal I45, switch I42 and terminal I43, back to the disc I 4|, sothere is a leakage path in shunt to resistance I34 in the section of therectifier from disc I25 to disc I24, as in Fig. 1. It will also be notedfrom the circuit description above that the resistance I is shunted outof the circuit. The circuit of Figs. 3 and 4, therefore, with the switchin its upper position (Fig. 3) for alternating current operation, isidentical with the circuit of Figs. 1 and 2, while with the switch I42in its lower position for direct current operation the rectifier isshunted entirely out of the circuit and resistance I50 is placed inseries with the load.

Referring again to Fig. 1, the successful operation of this device ispossible because of the novel manner of assembling the discs of therectifier shown in that figure. Whenever there is a positive half cycleof current applied to the terminal I21 there is a certain amount ofleakage current through the rectifier between discs I2I and I24 anddiscs I25 and I26 in spite of the fact that these discs are arranged notto pass current in this direction. By including a rectifier unit betweenthe discs I24 and I25 this leakage current is by-passed during one halfcycle without changing the circuit characteristics during the other halfcycle.

By breaking the contacts I3I and I32 at each operation of the machinethe drawing of excess or unneeded current through the rectifier and alsoits overheating is prevented but at the same time sufficient voltage andcurrent for efiicient operation of the machine is provided. The leakagepath provided in parallel with the load circuit across the middlesection of the rectifier serves an important function in the operationof the circuit.

In Fig. 7 I have shown an alternative circuit for half waverectification in which only two sections of a rectifier assembly areused, each section comprising ten discs or junctions. It will beunderstood that each of the sections I22, I23 is arranged similarly tothose already described in Figs. 1 and 8, except that they are of tenjunctions each. This circuit is identical with those already describedin connection with Figs. 1, 2, 3, and 4 except for the arrangement ofthe rectifier and the provision of a doublepole, double-throw switchI81. In this case when a D. C. supply is used positive potential must beapplied to terminal I28. The contacts are the same as above described,that is both switches I3I, I32 and I36, I31 are opened by the magnet 83upon its operation. The double pole, double-throw switch I81 has twoterminals I88, I9! which are closed for D. C. operation by throwing theswitch to the left and connecting termi- I89 with I88 and terminal I92with ISI. This ca .ses the coils of the magnet 83 to be arranged series.This arrangement is provided due to the fact that the voltage applied tothe magnet coils for D. C. operation with this circuit is double thatapplied to the magnet coils when operating from A. C. When operatingfrom A. C. the poles in the switch I81 are closed to the right to makecontact between terminals I89 and I96 and between I92 and I93. Thiscauses the magnet coils to be arranged in parallel.

From the above description it will be apparent that this inventionresides in certain principles of construction and operation asillustrated in the drawings. It is recognized that those skilled in theart may readily vary the application of these principles and thestructure by which they are applied without departing from the scope ofthe invention. I do not, therefore, desire to be strictly limited to thedisclosure as given, but rather to the scope of the appended claims.

What I claim as new, and desire to secure by Letters Patent, is:

1. A circuit for the output of a dry contact rectifier, said circuitcomprising thirty unilaterally conductive discs stacked in concentricalignment and arranged in three sections, the two outer sections of tendiscs each so stacked as to pass current in one direction and theintermediate section of ten discs so stacked as to pass current in theopposite direction.

2. A rectifier circuit for converting alternating current into pulsatingcurrent comprising a stack of unilaterally conductive discs arranged inthree sections in series across the alternating current supply, saidsections composed of a plurality of rectifier discs of the copper oxidetype, the two outer of said sections so arranged as to pass current inone direction, and the intermediate section arranged to pass current inthe opposite direction.

3. A rectifier circuit for converting alternating current into pulsatingcurrent comprising a stack of unilaterally conductive discs arranged inthree sections in series across the alternating current supply, saidsections composed of a plurality of rectifier discs of the copper oxidetype, the two outer of said sections so arranged as to pass current inone direction, and the intermediate section arranged to pass current inthe opposite direction, and a load circuit connected in parallel withthe intermediate section.

4. A rectifier circuit for converting alternating current into pulsatingcurrent comprising a plurality of unilaterally conductive discs of thecopper oxide type stacked in concentric alignment and divided into threesections, the end sections arranged to pass current in one direction andthe central section arranged to pass current in the reverse direction,and a load circuit connected in parallel with the central section.

EDWIN O. ROGGENSTEIN.

